Effect of the Fe doping over V-Sb oxide catalyst in toluene selective oxidation

ADRIANA ROMERO; BEATRIZ IRIGOYEN; SUSANA LARRONDO; SILVIA JACOBO; NORMA AMADEO

CATALYSIS TODAY

Elsevier

Lugar: Amsterdam; Año: 2008 vol. 133 p. 775 - 779

0920-5861

Mixed oxides FexV1x SbO4 with x = 0?1.0 were prepared by slurry method and characterized by X-ray diffraction (XRD), Mo¨ssbauer spectroscopy, and temperature-programmed reduction (TPR). The samples with x = 0, 0.4 and 1.0 were evaluated as catalyst in vapor phase toluene partial oxidation reaction. It was found by XRD that Fe, as doping, was introduced in the rutile structure of VSbO4. The BET surface area of partially substituted solid with x = 0.4 was higher than those obtained for VSbO4 and FeSbO4 samples. It was shown that V is responsible of the hydrocarbon molecule activation. The catalyst with Fe x = 0.4 presented lower specific rate reaction and lower selectivity to total oxidation products than undoped solid (VSbO4), which it would be related to a partial replace of V by Fe in the V-O-V chains. In conclusion, the solid activity and selectivity to total oxidation decrease due to a higher isolation of V sites, when V3+ is substituted by Fe3+ in the rutile structure.